Plug-In Electric Vehicle Interlock

ABSTRACT

To prevent damage of a cord set used to charge a plug-in electric vehicle when the vehicle is driven away while the cord set is attached, an interlock can be provided to disable the vehicle. Such interlock may be based on a protective door over the charging receptacle being open or detection that a cord set is plugged in. However, in the event that the vehicle is in an activated state, the interlock is prevented from disabling the vehicle according to an embodiment of the disclosure. That is, undesirable disabling of the vehicle is prevented when either there is no indication of a cord set being coupled to the vehicle or the vehicle is in an activated state.

BACKGROUND

1. Technical Field

The present disclosure relates to interlocks related to the chargingsystem on electric vehicles to disable vehicle driveaway duringcharging.

2. Background Art

Electric vehicles, which are coupled to a wall outlet to charge thebattery, are sometimes provided with an interlock such that vehiclestarting is prevented when the electric vehicle's cord set is pluggedinto the wall. As the vehicle may depend on being charged, there is aconcern that the cord set and/or the vehicle would be damaged in theevent of a driveaway while the cord set is attached.

The interlock may be a switch coupled to a protective door over thevehicle's receptacle. When the switch indicates that the door is open,driveaway is prevented. In another alternative, an electronic controlunit (ECU) onboard the vehicle determines whether the cord set isattached and, if so, prevents driveaway.

It may be possible for a vandal, or other third party, to interfere withthe vehicle's operational capability by opening the protective door orby plugging a device into the vehicle's receptacle to deceive the ECU'slogic associated with the cord set. Such a situation is not onlyinconvenient for the vehicle operator, but could leave the vehicleoperator stranded if the vehicle operator is unable to detect the issuepreventing vehicle operation.

SUMMARY

To overcome at least one problem, an interlock for a plug-in vehicleincludes enabling the vehicle when a negative result from a cord setindicator is detected, enabling the vehicle when a positive result fromthe cord set indicator is detected immediately following detection of anegative result from the cord set indicator while the vehicle iscontinuously is activated, and disabling the vehicle when a positiveresult from a cord set indicator is detected while the vehicle isdeactivated. In one embodiment, enabling is allowing a powertrain of thevehicle to provide propulsion to wheels of the vehicle in response to anaction of a vehicle operator to activate the vehicle. In one embodiment,an activated state of the vehicle is when the vehicle is in atorque-producing mode. Alternatively, the activated state includes atransmission of the vehicle being in one of a forward or reverse drivinggear.

The vehicle has at least one electric motor coupled to vehicle wheelsand disabling the vehicle is performed by preventing the electric motorfrom providing propulsive force to vehicle wheels. The vehicle mayfurther include an internal combustion engine coupled to vehicle wheels.Disabling the vehicle may further include preventing the internalcombustion engine from providing propulsive force to vehicle wheels.

The vehicle has a charging receptacle with a protective door providingaccess to the charging receptacle and a switch mounted proximate theprotective door. The cord set indication is provided by the switch.Alternatively, the cord set indicator is based on detecting electricalproperties consistent with a cord set being coupled to the receptacle onthe vehicle.

An interlock for a plug-in vehicle includes a cord set indicator and anelectronic control unit coupled to a powertrain of the vehicle and thecord set indicator. An interlock routine of the electronic control unitdisables the powertrain when the cord set indicator indicates that acharging cord is attached to the vehicle and the vehicle is deactivatedand prevents disabling of the powertrain when the vehicle is activated.The vehicle is activated when the vehicle is in a torque-producing modesuch that an operator of the vehicle may selectively command propulsionat vehicle wheels without manipulation related to the cord setindicator. The interlock may also include a charging receptacle coupledto the vehicle, a charge door coupled to the vehicle and preventingaccess to the charging receptacle when in a closed position, and aswitch coupled to the charge door and electronically coupled to theelectronic control unit. A signal from the switch indicates whether thedoor is open or closed and the switch is the cord set indicator. In analternative embodiment, the interlock includes a charging receptaclecoupled to the vehicle and electronically coupled to the electroniccontrol unit. The electronic control unit detects whether a plug iscoupled with the charging receptacle and detection of the plug is thecord set indicator. The electronic control unit prevents disabling ofthe vehicle when the vehicle is presently activated regardless of astatus of the cord set indicator. The interlock may further include acharging receptacle coupled to the vehicle and electronically coupled tothe electronic control unit, and an operator indicator within a cabin ofthe vehicle. The electronic control unit turns on the operator indicatorwhen the cord set indicator indicates that a plug is coupled to thecharging receptacle.

According to an alternative embodiment, an interlock method for aplug-in vehicle includes preventing the vehicle from accessing atorque-producing mode when both a positive result from a cord setindicator is detected and the vehicle is in a deactivated state; andallowing the vehicle to access the torque-producing mode in response toone of: a negative result from a cord set indicator and the vehiclecurrently in an activated state. The torque-producing mode is preventedby one of disabling a powertrain of the vehicle and preventing atransmission coupled to the vehicle from accessing any forward orreverse gear. The vehicle has a receptacle adapted to accept a cord setfor charging of the vehicle, the vehicle has a protective door to coverthe receptacle, the vehicle has a switch proximate the protective door,and the cord set indicator is based on a signal from the switchindicating whether the protective door is open. The vehicle has areceptacle adapted to accept a cord set for charging of the vehicle andthe cord set indicator is based on detecting presence of the cord setcoupled to the receptacle.

The torque-producing mode is a mode in which the vehicle is capable ofbeing propelled via commands by a vehicle operator by depressing anaccelerator pedal coupled to the vehicle. According to anotherembodiment, the torque-producing mode is a state of the vehicle in whicha vehicle operator selectively commands a powertrain of the vehicle topropel the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of a plug-in hybrid electric vehicle; and

FIG. 2 is a flowchart depicting one embodiment of the presentdisclosure.

DETAILED DESCRIPTION

As those of ordinary skill in the art will understand, various featuresof the embodiments illustrated and described with reference to any oneof the Figures may be combined with features illustrated in one or moreother Figures to produce alternative embodiments that are not explicitlyillustrated and described. The combinations of features illustratedprovide representative embodiments for typical applications. However,various combinations and modifications of the features consistent withthe teachings of the present disclosure may be desired for particularapplications or implementations. Those of ordinary skill in the art mayrecognize similar applications or implementations consistent with thepresent disclosure, e.g., ones in which components are arranged in aslightly different order than shown in the embodiments in the Figures.Those of ordinary skill in the art will recognize that the teachings ofthe present disclosure may be applied to other applications orimplementations. In FIG. 1, a schematic of a vehicle is shown by way ofexample as a plug-in hybrid electric vehicle (HEV) 10. One type of HEVin which powertrain 11 includes: an internal combustion engine, aone-way clutch 14, a generator 16, a planetary gear set 18, and motor20. Powertrain 11 is coupled to differential 22. Differential 22 iscoupled to the axle having drive wheels 24. Vehicle 10 also hasnon-driven wheels 26.

The HEV in FIG. 1 has a high voltage battery 28, which is coupled togenerator 16 and motor 20. Electronic control unit (ECU) 30 is coupledto engine 12, one-way clutch 14, generator 16, motor 20, and battery 28.In FIG. 1, a single ECU 30 is illustrated. However, it is common forvehicle 10 to have distributed computing involving multiple ECUs insteadof a single ECU. For illustration purposes and ease of description,computing and control functionality is described in regards to a singleECU with the understanding that such functionality can be separatedamong multiple processors.

Vehicle 10, as a plug-in, has an electrical receptacle 32 with aprotective door 34, which is shown in FIG. 1 in an open position.Vehicle 10 has a charger, which in FIG. 1 is integrated into electricalreceptacle 32, but could be in a separate module in an alternativeembodiment. A pin switch 35 is provided on vehicle 10 proximateprotective door 34. Protective door 34 keeps away from dirt, dust, andmoisture from the environment when charging is not occurring. A chargingcord set 36 includes: an electrical coupler 38, which couples withreceptacle 32 during charging; two lengths of cable 40 with anelectrical vehicle supply equipment (EVSE) 42 device in between cables40. In some embodiments, EVSE 42 includes fuses, relays, transformers,and a circuit board with processing capability. Cord set 36 furthercomprises a plug 44 which can be plugged into wall outlet 46.

Vehicle 10 in FIG. 1 is a HEV; but in an alternative embodiment vehicle10 is a battery-only electric vehicle. Furthermore, other HEVarchitectures are within the scope of the present disclosure.

Cord set 36 can be damaged if vehicle 10 were started up and driven awaywhen cord set 36 is coupled to vehicle 10. To avoid such damage, aninterlock system can be provided in which ECU 30 prevents powertrain 11from driving away in response to a cord set indicator, i.e., indicatingwhether a cord set is coupled to the vehicle. In one embodiment,two-position pin switch 35 indicates to ECU 30 whether the door is openor closed. The door being open provides an indication that a cord set iscoupled with the vehicle. In embodiments in which the door is used asthe charging indicator, interlock actions are taken regardless ofwhether a cord set is actually coupled to the vehicle and whether or notactual charging is occurring. In some embodiments, ECU 30 provides asignal to an operator indicator 50 so that the operator of the vehicleis informed and can attend to the fault. Operator indicator 50 canprovide a written, symbolic, oral, or any suitable signal to indicate afault to the operator of vehicle 10.

In an alternative embodiment, ECU 30 detects whether an electricalcoupler is coupled with receptacle 32. This can be accomplished via aswitch proximate receptacle 32, similar to pin switch 35, whichelectrical coupler 38 actuates when installed. In another embodiment,ECU 30 detects whether a cord set is coupled with receptacle 32 based onelectrical properties. Depression of a pin associated with receptacle 32or electrical properties is one embodiment of a cord set indicator. Aswith door switch 35, a pin switch proximate receptacle 32 indicating thepresence of an electrical coupler or the change in electrical propertiesdetermined can be used as a cord set indicator. An inadvertentdepression of the pin or an alternative to electrical coupler 38 can becoupled with receptacle 32, either of which would provide a positiveresult in the cord set indictor whether or not a cord set is actuallycoupled to the vehicle. An alternative to electric coupler 38 couldinclude an element having one or more components that mates withreceptacle 32 and mimics the electrical properties of the cord set 36 sothat ECU 30 detects the presence of a cord set. For example, theresistance characteristics of cord set 36 can be matched by the element.

As door 34 and receptacle 32 are external to vehicle 10, a prankster candisable the vehicle by opening door 34 in embodiments in which door 34provides the cord set indicator signal or by popping in an electric plugcontaining some circuitry to provide a cord set indication. Or, aninnocent third party can inadvertently disable the vehicle, e.g., byforgetting to close door 34 when disconnecting cord set 36 or catchingdoor 34 on clothing causing it to open. In yet another example, a fenderbender may cause protective door 34 to open and thereby disablingvehicle 10. In the event that vehicle 10 is, for example, parked in agarage, operator indicator 50 provides the operator with information toresolve the situation, which is preventing vehicle 10 from driving away.However, such an interlock presents a problem when vehicle 10 isactivated. For example, if vehicle 10 is stopped at a traffic light anda pedestrian bumps the car causing protective door 34 to open, vehicle10 becomes disabled, which at a minimum is an inconvenience to thevehicle operator. It is desirable to prevent the interlock fromdisabling vehicle 10 when it is already activated, i.e., a conditionunder which a cord set is exceedingly unlikely to be plugged in. If thecord set indicator is providing a positive result, under suchcircumstances, it is more than likely providing a false indication thata cord set is actually coupled to vehicle 10. Instead it can beproviding a positive result by the door being open or a dummy plugcoupled to the vehicle receptacle, i.e., a false positive.

In FIG. 2, a flowchart, according to one embodiment of the disclosure,starts in 100. In block 102, it is determined whether the vehicle isactivated. In one embodiment, an activated vehicle occurs at key-on,i.e., the operator of the vehicle has used a key of the vehicle to bringthe vehicle into a state in which the vehicle could be caused to moveupon accessing a gear and providing input to an accelerator pedal. Somevehicles are not provided with an ignition key, but instead arepush-button started, which is allowed only when the ignition systemdetects a radio frequency identification device with the appropriatecode within the vehicle or other suitable device and the operator haspushed a button to activate the vehicle. In such case, key-on refers tothe state in which the vehicle operator could cause the vehicle to moveby accessing a gear and pushing on an accelerator pedal. Such activatedstate is independent of whether an electric motor or an internalcombustion engine associated with the vehicle is rotating. For example,neither the electric motor of the internal combustion engine, ifprovided in the vehicle, may be rotating when the vehicle is stopped ata traffic light. Nevertheless, the vehicle is considered to be activatedas propulsion can be requested by the operator simply by depressing theaccelerator pedal (without the brake being applied). Such activatedstate can alternatively be called torque-producing mode orpropulsion-ready mode. Herein, the vehicle being disabled refers to thevehicle being rendered unable to propel the vehicle via normal operatoractions. Normal operator actions are those which cause the vehicle toaccess the torque-producing mode, such as putting the transmission intoa gear, releasing a brake pedal, and/or depressing an accelerator pedal.In background systems, the vehicle becomes disabled upon an interlockcondition occurring and is not enabled until the interlock condition isremoved. The vehicle may be come enabled by the operator taking care ofthe situation leading to the interlock condition. However, for thepurposes of this disclosure, such actions to overcome the interlockcondition are not considered normal operator actions to put the vehiclein the torque-producing mode. Furthermore, such normal operator actionsdo not include the vehicle operator, or other actor, taking action fromoutside a cabin of the vehicle. Such non-normal actions occurringoutside the cabin may include unplugging the cord set 36, closing theprotective door 34, as examples.

Referring again to FIG. 2, if a positive result in 102, control passesto 104 in which an indication of a cord set 36 coupled with receptacle32 is detected. If such indication is found, control passes to block 106in which a warning message is displayed on the operator indicator. Suchmessage can be a text message, an oral message, a chime, an indicatorlamp, etc. A negative result in block 104 and 106 pass control to 108 inwhich the interlock is prevented and the vehicle is allowed to continueto remain activated.

If a negative result in block 102, control passes to block 110, in whichcord set coupling with receptacle 32 is determined. If a positive resultin block 110, control passes to block 112 in which the interlock isactuated, meaning that the vehicle is disabled. In one embodiment, thevehicle is disabled by disabling the powertrain, i.e., neither theengine nor motor can be caused to rotate. In another embodiment, thepowertrain may be allowed to rotate to provide secondary functions, butthe vehicle is disabled by preventing taking the transmission out ofpark. From block 112, control passes to 114 in which it is determinedwhether there was an attempted start. If yes, the operator indicatormessage is activated in block 116 to provide the operator withinformation about the fault so that the operator may rectify thesituation and remove the condition leading to the interlock. If anegative result in block 114, control passes to block 118 in whichcharging of the vehicle is allowed.

If a negative result in block 110, control passes to block 120 in whichthe interlock is not activated so that the vehicle will be allowed tostart (enabled) when such command is given by the vehicle operator. Theroutine can be run successively with control passing back to block 102from any of blocks 108, 118, and 120.

While the best mode has been described in detail, those familiar withthe art will recognize various alternative designs and embodimentswithin the scope of the following claims. Where one or more embodimentshave been described as providing advantages or being preferred overother embodiments and/or over background art in regard to one or moredesired characteristics, one of ordinary skill in the art will recognizethat compromises may be made among various features to achieve desiredsystem attributes, which may depend on the specific application orimplementation. These attributes include, but are not limited to: cost,strength, durability, life cycle cost, marketability, appearance,packaging, size, serviceability, weight, manufacturability, ease ofassembly, etc. A suitable compromise, depending on the application, maybe selected. The embodiments described as being less desirable relativeto other embodiments with respect to one or more characteristics are notoutside the scope of the disclosure as claimed.

1. An interlock method for a plug-in vehicle, comprising: enabling thevehicle when a negative result from a cord set indicator is detected;enabling the vehicle when a positive result from the cord set indicatoris detected immediately following detection of a negative result fromthe cord set indicator while the vehicle is continuously is activated;and disabling the vehicle when a positive result from a cord setindicator is detected while the vehicle is deactivated.
 2. The method ofclaim 1 wherein enabling comprises allowing a powertrain of the vehicleto provide propulsion to wheels of the vehicle in response to an actionof a vehicle operator to activate the vehicle.
 3. The interlock methodof claim 1 wherein an activated state of the vehicle comprises thevehicle being in a torque-producing mode.
 4. The interlock method ofclaim 3 wherein the activated state comprises a transmission of thevehicle being in one of a forward or reverse driving gear.
 5. Theinterlock of claim 1 wherein the vehicle has at least one electric motorcoupled to vehicle wheels and the disabling the vehicle comprisespreventing the electric motor from providing propulsive force to vehiclewheels.
 6. The interlock of claim 5 wherein the vehicle furthercomprises an internal combustion engine coupled to vehicle wheels andthe disabling the vehicle further comprises preventing the internalcombustion engine from providing propulsive force to vehicle wheels. 7.The interlock method of claim 1 wherein the vehicle has: a chargingreceptacle with a protective door providing access to the chargingreceptacle; and a switch mounted proximate the protective door, theswitch comprising the cord set indicator.
 8. The interlock method ofclaim 1 wherein the cord set indicator is based on detecting electricalproperties consistent with a cord set being coupled to the receptacle onthe vehicle.
 9. An interlock for a plug-in vehicle, comprising: a cordset indicator; an electronic control unit coupled to a powertrain of thevehicle and the cord set indicator wherein an interlock routine of theelectronic control unit disables the powertrain when the cord setindicator indicates that a charging cord is attached to the vehicle andthe vehicle is deactivated and prevents disabling of the powertrain whenthe vehicle is activated.
 10. The interlock of claim 9 wherein thevehicle being activated comprises the vehicle being in atorque-producing mode such that an operator of the vehicle mayselectively command propulsion at vehicle wheels without manipulationrelated to the cord set indicator.
 11. The interlock of claim 9, furthercomprising: a charging receptacle coupled to the vehicle; a charge doorcoupled to the vehicle and preventing access to the charging receptaclewhen in a closed position; a switch coupled to the charge door andelectronically coupled to the electronic control unit wherein a signalfrom the switch indicates whether the door is open or closed and theswitch comprises the cord set indicator.
 12. The interlock of claim 9,further comprising: a charging receptacle coupled to the vehicle andelectronically coupled to the electronic control unit wherein theelectronic control unit detects whether a plug is coupled with thecharging receptacle and detection of the plug comprises the cord setindicator.
 13. The interlock of claim 9 wherein the electronic controlunit prevents disabling of the vehicle when the vehicle is presentlyactivated regardless of a status of the cord set indicator.
 14. Theinterlock of claim 9, further comprising: a charging receptacle coupledto the vehicle and electronically coupled to the electronic controlunit; and an operator indicator within a cabin of the vehicle whereinthe operator indicator is electronically coupled to the electroniccontrol unit wherein the electronic control unit turns on the operatorindicator when the cord set indicator indicates that a plug is coupledto the charging receptacle.
 15. An interlock method for a plug-invehicle, comprising: preventing the vehicle from accessing atorque-producing mode when both a positive result from a cord setindicator is detected and the vehicle is in a deactivated state; andallowing the vehicle to access the torque-producing mode in response toone of: a negative result from a cord set indicator; and the vehiclecurrently in an activated state.
 16. The interlock method of claim 15wherein the torque-producing mode is prevented by one of disabling apowertrain of the vehicle and preventing a transmission coupled to thevehicle from accessing any forward or reverse gear.
 17. The interlockmethod of claim 15 wherein the vehicle has a receptacle adapted toaccept a cord set for charging of the vehicle, the vehicle has aprotective door to cover the receptacle, the vehicle has a switchproximate the protective door, and the cord set indicator is based on asignal from the switch indicating whether the protective door is open.18. The interlock method of claim 15 wherein the vehicle has areceptacle adapted to accept a cord set for charging of the vehicle andthe cord set indicator is based on detecting presence of the cord setcoupled to the receptacle.
 19. The interlock method of claim 15 whereinthe torque-producing mode is a mode in which the vehicle is capable ofbeing propelled via commands by a vehicle operator by depressing anaccelerator pedal coupled to the vehicle.
 20. The interlock method ofclaim 15 wherein the torque-producing mode comprises a state of thevehicle in which a vehicle operator selectively commands a powertrain ofthe vehicle to propel the vehicle.